Apparatus for use by skiers on which they may simulate the motions, exertions and techniques required in skiing has been built and sold for several years. In particular U.S. Pat. No. 3,524,641 was issued to Robert J. Ossenkop on Aug. 18, 1970, for a device comprising a movable carriage on a set of rails. The carriage of that device is constrained in its movement on the rails by flexible members attached to both the carriage and to transverse members between the rails near each end of the set of rails, and a user can move the carriage from side to side on the rails to simulate the Wedeln or "parallel" technique of skiing.
U.S. Pat. No. 3,547,434 was issued to the same inventor on Dec. 15, 1970. This later referenced patent is for a device similar to the first device, but comprising a number of improvements, such as moveable platforms acting as footrests on the carriage whereby a user may simulate turning and edging techniques in addition to parallel skiing, and in some embodiments may also move the feet relative to one another.
The inventions referenced above each include a safety strap attached to a transverse member between the parallel rails and to the carriage on the rails in addition to the flexible member by which the carriage is constrained to travel on the rails. The purpose of the safety strap is to provide for the situation in which the aforementioned flexible member might rupture on one side of the carriage, providing a sudden force urging the carriage to the side where the flexible member remains unruptured, which sudden force could dislodge a user and perhaps cause serious injury. The safety strap in such instance provides a restoring force toward the center tending to lessen the amplitude of carriage displacement that might otherwise occur.
On May 10, 1988 U.S. Pat. No. 4,743,014 issued to R. Joel Loane, the present inventor, for a device similar to the devices taught by Ossenkop. The device patented to Loane on May 10, 1988 has a pair of spaced apart rails, a platform for riding on the rails, a first resilient element providing a first restoring force on the platform, and a second resilient element providing a second restoring force on the platform. The second resilient element has an adjustment element contacting the second resilient element in at least three points.
The copending parent application to the instant application, Ser. No. 178,354, discloses and claims improvements to the device of U.S. Pat. No. 4,743,014. One improvement is a longer first resilient element passing around roller elements at the ends of the device and fastening to a centrally located brace element. Another improvement is an off-center mounting of each of two foot pad platforms on the riding carriage, placing the pivot of each somewhat toward the edge of each away from the other platform, so the weight of a user and his action in shifting his weight in operating the ski exerciser will cause each platform to initially rotate in the correct direction to simulate edging technique.
In all of the ski exercising apparatus thus far, as illustrated by the above referenced patents and pending application, there are two foot platforms, one for each of a user's feet, and the platforms are mounted to other elements of the exerciser in each instance by apparatus, such as pivot rods, that is mounted below each foot platform. In marketing these devices, it has become apparent that there are users who wish to use such a device, but find the devices difficult to use or not suited to the particular use they desire. These potential users want a device with a single foot platform. Some have only one leg. Others simply wish to exercise with one leg at a time to place more stress and demand on the one leg used. Accordingly a device is needed with a single foot platform, and mounted and operable to serve the needs of the aforementioned potential users.